Substrate plating device

ABSTRACT

A plating device includes a pl,ting bath containing therein a plating solution, a substrate holder for detachably holding a substrate, an anode disposed opposite to the substrate held by the substrate holder, a rail part stretched across an upper portion of the plating bath in parallel to the substrate holder, and a paddle suspended by the rail part and capable of reciprocating along the rail part. The paddle is vertically provided with a vane part rotatable round or pivotable on an axis part. The plating device can increase flow rate of a plating solution without installing a circulating pump outside a plating bath, and further can achieve same flow rate of the plating solution from a bottom of the plating bath to a level of the solution, enabling plating that forms a plating film having a uniform thickness on an entire region of a substrate and exhibits a high deposition rate.

TECHNICAL FIELD

The present invention relates to a plating device in which a substrate is immersed in a plating solution to subject the surface of the substrate to plating.

BACKGROUND ART

Conventionally, with respect to a plating device for a semiconductor substrate in which a plating jig having a substrate held is vertically set and a plating solution is allowed to flow into a plating bath from the bottom of the bath and to overflow the top of the bath, one has been known in which a paddle capable of reciprocating between the plating jig and an anode is provided so as to uniformly feed the plating solution to the entire region of the surface of the substrate to be plated during the plating treatment.

In the case of stirring using such a paddle, a substrate is held by a plating jig and subjected to plating while allowing the paddle to reciprocate, but the direction of the liquid flow and the traveling direction of the paddle are reversed to cause an alternate change of the direction of the liquid flow, and hence a problem occurs in that the flow rate at the surface cannot be increased.

For solving the above problem, PTL 1 discloses a plating device in which, using a swirl generator for generating a swirling flow in a plating solution, a swirling flow is generated in the plating solution supplied from the lower portion of a plating bath.

However, in such a plating device, a circulating pump for feeding the plating solution to the swirl generator must be installed outside the plating bath, and an increased space for the installation is required. In addition, the plating solution is fed to the swirl generator from the lower portion of the plating bath, and therefore it is difficult to make uniform the flow rate at the top and bottom of the surface to be plated.

PTL 1: JP-A-2004-345066

SUMMARY OF INVENTION Technical Problem

Accordingly, a task of the present invention is to solve the above-mentioned problems accompanying a conventional plating device, and to provide a plating device which can increase the flow rate of a plating solution without installing a circulating pump outside the plating bath, and further can achieve the same flow rate of the plating solution from the bottom of the plating bath to the level of the solution, enabling a plating treatment forming a plating film having a uniform thickness on the entire region of the substrate and exhibiting a high deposition rate.

Solution to Problem

The invention has been made in order to solve the above-mentioned problems, and is directed to a plating device which includes a plating bath containing therein a plating solution, a substrate holder for detachably holding a substrate, an anode disposed opposite to the substrate held by the substrate holder, a rail part stretched across above the plating bath so as to be in parallel to the substrate holder, and a paddle being suspended by the rail part and being capable of reciprocating along the rail part, wherein the plating device is characterized in that the paddle is vertically provided with a vane part rotatable round or pivotable on an axis part.

Advantageous Effects of Invention

In the plating device of the invention, by providing the paddle capable of reciprocating along the rail part with a rotatable or pivotable vane part, the flow rate or direction of the flow hit the substrate can be controlled, so that the flow evenly hits the entire surface of the substrate, making it possible to achieve a plating film having a uniform thickness.

Further, in the plating device of the invention wherein the vane part of the paddle is rotated in a constant direction all the time, the liquid flow near the surface of the substrate to be plated is unidirectional, so that even less power can cause the liquid flow to hit the surface of the substrate at a high speed.

Furthermore, in the plating device of the invention wherein the vane part of the paddle is pivoted (swung) in a predetermined range of the angle, the liquid flow vertically hits the surface of the substrate W to be plated, and further the flow hits the entire surface of the substrate W, making it possible to subject the substrate uniformly to plating treatment.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] A diagrammatic plan view of the plating device of the invention

[FIG. 2] A diagrammatic cross-sectional view of the plating device of the invention

[FIG. 3] A diagrammatic plan view of a plating device according to another embodiment of the invention

[FIG. 4] A diagrammatic cross-sectional view of the plating device according to another embodiment of the invention

[FIG. 5] (a) A front view showing an embodiment of the paddle of the plating device of the invention, and (b) a cross-sectional view showing an embodiment of the paddle of the plating device of the invention

DESCRIPTION OF EMBODIMENTS

Hereinbelow, the plating device according to an embodiment of the present invention will be described in detail with reference to the drawings. The embodiments should not be construed as limiting the scope of the invention.

FIG. 1 is a diagrammatic plan view of the plating device of the invention, and FIG. 2 is a diagrammatic top view of the plating device of the invention. As shown in the figures, the plating device of the invention includes a plating bath 1 containing therein a plating solution, a substrate holder 2 for detachably holding a substrate, an anode 3 disposed opposite to a substrate W held by the substrate holder 2, a rail part 5 stretched across an upper portion of the plating bath 1 so as to be in parallel to the substrate holder 2, and a paddle 4 being suspended by the rail part 5 and being capable of reciprocating along the rail part 5. Hereinbelow, the members are individually described.

As shown in the figures, the rail part 5 is stretched across above the plating bath 1 between the substrate holder 2 and the anode 3 so as to be in parallel to the substrate holder 2. From the rail part 5 is suspended the paddle 4 having a driving means (not shown) for permitting the paddle to reciprocate back and forth along the rail part 5. The paddle 4 has a motor 43 which is a driving means for the rotation of a vane part 41, and has vertically formed an axis part 42 rotatable in cooperation with the motor 43.

In the axis part 42 of the paddle 4, two vane parts 41 protruding respectively in the opposite directions are formed so as to be rotatable by a force of rotation transferred from the motor 43 through the axis part 42. In the present embodiment, the vane parts 41 are formed to have a rectangular form in cross-section, but may be formed into an arc form having a concave surface in the rotating direction of the impeller. By forming such a concave surface, the vane parts 41 can efficiently capture the plating solution to improve the flow rate. With respect to the number of the vane parts 41, there is no particular limitation, but two vane parts are especially preferred. Further, with respect to the width of the vane part 41 (length in the vertical direction as viewed on the drawing), the vane part desirably has a width which can cover at least the height of the surface of the substrate W to be plated.

The paddle 4 in the present embodiment reciprocates back and forth along the rail part 5, and, in this instance, the vane part 41 is rotated in the same direction all the time. For example, in the embodiment of FIG. 1, the vane part 41 is rotated in a clockwise direction all the time during the reciprocation of the paddle 4. Thus, when the direction of rotation of the vane part 41 is constant all the time, irrespective of the traveling direction of the paddle 4, the liquid flow near the surface of the substrate W to be plated is unidirectional, so that even less power can cause the liquid flow to hit the surface of the substrate at a high speed.

FIGS. 3 and 4 show a plating device according to the second embodiment of the invention. The plating device of the second embodiment is the same as the plating device of the first embodiment in a point that the paddle 4 suspended by the rail part 5 stretched across above the plating bath 1 is capable of reciprocating. The second embodiment has a characteristic feature in the following point. That is, in the present embodiment, the vane part 41 of the paddle 4 is formed to be pivotable (swingable) by a motor 43 in a predetermined range of the angle. Specifically, the vane part 41 provided so as to protrude in the direction of from the axis part 42 to the substrate W is pivoted from side to side from the position perpendicular to the substrate W as indicated by an arrow in the figure. In this case, with respect to the pivot angle of the vane part 41, there is no particular limitation, but, for causing a liquid flow efficiently using the minimum power, the pivot angle is preferably set to be in the range of from 30 to 90 degrees (an angle of 15 to 45 degrees to the line perpendicular to the substrate W as a one side angle). Further, also with respect to the number of the vane part (s) 41, there is no particular limitation, but, when the number of the vane parts is increased, an unnecessary liquid flow is caused, and therefore one vane part as shown in the figure is preferred.

As mentioned above, in the second embodiment, while the vane part 41 is pivoted in a predetermined range of the angle, the paddle 4 reciprocates back and forth along the rail part 5, and therefore the liquid flow vertically hits the surface of the substrate W to be plated, and further the flow hits the entire surface of the substrate W, making it possible to subject the substrate uniformly to plating treatment.

In the plating device of the second embodiment, the paddle 4 may be moved while maintaining the vane part 41 at a constant angle to the traveling direction of the paddle 4 without permitting the vane part 41 to pivot. By this method, the liquid flow can efficiently hit the surface of the substrate W to be plated, and therefore even less power can subject the substrate uniformly to plating treatment.

Further, in the plating device of the second embodiment, the paddle 4 may be provided with a stopper which holds the vane part 41 so as to freely pivot and limits the pivot angle of the vane part 41 to a predetermined range. In this embodiment, a resistance of the liquid against the vane part 41 is changed according to the traveling direction of the paddle 4, and therefore the direction and angle of the vane part 41 are changed or maintained in accordance with the movement of the paddle 4. Thus, the liquid flow can efficiently hit the surface of the substrate W to be plated, and therefore even less power can subject the substrate uniformly to plating treatment.

FIG. 5 shows another embodiment of the paddle of the plating device of the invention. The paddle in the present embodiment is of a so-called cross flow impeller type, and two vane parts 41 are vertically provided between upper and lower disc-form support parts 44 and symmetrically formed so as to have a portion for the axis of rotation between the vane parts. The vane parts 41 are formed to be rotatable round an axis part 42 connected to the upper support part 44 as an axis of rotation. Further, the paddle 4 in the present embodiment is provided with a cover 45 curved into a half-round form along the side surface opposite to the anode 3 side. Thus, when the paddle of the plating device of the invention is of a cross flow impeller type, the flow hits the entire surface of the substrate W, making it possible to subject the substrate uniformly to plating treatment.

REFERENCE SIGNS LIST

-   1: Plating bath -   2: Substrate holder -   3: Anode -   4: Paddle -   5: Rail part -   41: Vane part -   42: Axis part -   43: Motor part -   44: Support part -   45: Cover 

1-5. (canceled)
 6. A plating device comprising: a plating bath containing therein a plating solution; a substrate holder configured to detachably hold a substrate; an anode disposed opposite to the substrate held by the substrate holder; a rail part stretched across above the plating bath in parallel to the substrate holder; and a paddle suspended by the rail part and configured to reciprocate along the rail part; wherein the paddle vertically includes a vane part rotatable around or pivotable on an axis part.
 7. The plating device according to claim 6, wherein the vane part is rotated by a driving means in a same direction at all times.
 8. The plating device according to claim 6, wherein the vane part is pivoted by a driving means in a predetermined angular range.
 9. The plating device according to claim 6, wherein the vane part includes a pair of vane parts vertically provided between upper and lower disc-form support parts in the paddle to be rotatable around the axis part connected to the upper support part as an axis of rotation.
 10. The plating device according to claim 9, wherein the paddle includes a cover curved into a half-round form along a side surface. 